xylem 0.9.1

Convert Python Abstract Syntax Trees to readable source code

Convert Python Abstract Syntax Trees (ASTs) to readable source code.

Xylem is useful for when you want to make dynamic changes to Python code/ASTs, but also need to write those changes back as source code.

It’s also very small (~600 lines), and pure-Python, and produces (mostly) readable source code.

In writing this, I made heavy use of the unofficial AST documentation at Green Tree Snakes.

Installation

Xylem will work on Python 3.4 or later. I’ll eventually get around to testing it on Python 2.7-3.3.

From PyPI

Install Xylem by running pip3 install xylem from the command line.

Note

On some Linux systems, installation may require running pip with root permissions, or running pip3 install xylem --user. The latter may require exporting ~/.local/bin to PATH.

From GitHub

Clone or download the git repo, navigate to the directory, and run:

python3 setup.py sdist
cd dist
pip3 install xylem-<version>.tar.gz

Usage

to_source is likely the only method you’ll need to use:

>>> from xylem import to_source
>>> import ast
>>> tree = ast.parse("print('hello world')")
>>> ast.dump(tree)
"Module(body=[Expr(value=Call(func=Name(id='print', ctx=Load()), args=[Str(s='Hello world')], keywords=[]))])"
>>> to_source(tree)
"print('hello world')"

compare_ast may also be useful for determining if two ASTs are functionally equivalent.

Development

Xylem versioning functions on a MAJOR.MINOR.PATCH.[DEVELOP] model. Only stable, non development releases will be published to PyPI. Because Xylem is still a beta project, the MAJOR increment will be 0. Minor increments represent new features. Patch increments represent problems fixed with existing features.